In a DS-CDMA system the users communicate simultaneously using the same frequency band via orthogonal modulation or spread spectrum. The bandwidth of conventional S-CDMA systems is determined by the chip rate and the pulse shape filtering that is used. Many of these systems also use a look-up table to store the pseudo-noise (PN) spreading codes in the transmitter and receiver. This is particularly true for those types of system using PN codes that are a power of two in length.
Conventional DS-CDMA system employ a single fixed chip rate, and thus exhibit a fixed bandwidth. This can create a problem when it is desired to produce a waveform that is required to have more than one bandwidth, and/or when it is desired to implement the CDMA system in different regions and markets having differing spectrum use and allocation regulations. For example, if in a particular region an operator is allocated a bandwidth of X, where the CDMA system requires a bandwidth of Y and where X<Y, then it may be impossible to operate the system.